$A$ metal $M$ forms an oxide with the formula $M_{2}O_{3}$. It dissolves in both dilute sulphuric acid and dilute sodium hydroxide solution. Identify the metal and write the chemical equations for the reactions involved.

$Al_{2}O_{3(s)} + 2NaOH_{(aq)} \xrightarrow{\Delta} \dots + H_{2}O_{(l)}$

$A$ man went door to door posing as a goldsmith. He promised to bring back the glitter of old and dull gold ornaments. An unsuspecting lady gave a set of gold bangles to him which he dipped in a particular solution. The bangles sparkled like new but their weight was reduced drastically. The lady was upset but after a futile argument the man beat a hasty retreat. Can you play the detective to find out the nature of the solution he had used?

Out of the two metals $P$ and $Q$, $P$ is less reactive than $Q$. Suggest an activity to arrange these metals in the order of their decreasing reactivity. Support your answer with a suitable chemical equation.

How can metals be differentiated from non-metals on the basis of any three chemical properties?

Although metals form basic oxides,which of the following metals form an amphoteric oxide?